Wireless communication networks are becoming increasingly popular and co-exist with or may even replace traditional wireline communication networks. Wireless communication network enable users to wirelessly transmit information to other users, such as for a telephone conversation between users of telephone terminals or a data communication between computing devices. A mobile telephone is one type of wireless communication device which is widely used in voice and/or data communications. Similarly, a mobile computer may be used as a wireless communication device and may enabled to connect to a wireless communication network for data transmissions and/or for assisting in voice communications.
Wireless communication networks include mobile communication networks, such as networks according to the GSM (global system for mobile communications) standard, UMTS (universal mobile telephone system) and similar. Mobile devices can generally freely move within at least a coverage area of the mobile communication network, even during an ongoing communication. Another type of wireless communication network is a communication network for fixed wireless devices, i.e., devices which are wirelessly connected to the network, but are only allowed to move within a certain fixed local area of the coverage area of the wireless network during an ongoing communication.
A further type of wireless communication network is a wireless network with distributed medium access, i.e., a network without a central control facility for managing resources, etc. While many types of wireless communication networks employ a central control facility, wireless networks with distributed medium access control use a decentralized access to communication resources, essentially allowing the individual participants of the network to negotiate access to resources among one another.
An ad-hoc communications network may be configured as a wireless network with distributed medium access control, constituting a network with dynamic behaviour and composition, where an availability of resources and e.g. a coverage area depends on the participating network elements or nodes.
Various factors in association with technology, business, regulatory issues and social behaviour have driven the spreading of wireless ad-hoc networks. An ad-hoc network may consist of a plurality of wireless devices using a wireless interface for an exchange of data, such as packet data or continuous streams of data. Each wireless device may serve as a communication node, being responsible for forwarding data on behalf of other communication devices, and may at the same time be running user applications on behalf of a user of the communication device, such as communication services. Various kinds of ad-hoc networks exist, including networks having mobile nodes and/or fixed wireless nodes, networks that rely on packetized data transfer, or on direct communication links or any kind of connection-less links.
In a typical communication network with distributed access control, to establish a communication link between two parties, a communication path is established through a number of communication devices or network nodes participating in the relaying of the data between the two communicating parties, i.e., nodes relay information or data packets on behalf of other nodes. This approach is termed multi-hopping and allows advantages such as a better reuse of resources of the network and a decrease of a transmit power of the system, since the individual ‘hops’ between nodes only involve a short distance which can be covered without requiring large transmission power.
One standard for wireless communication networks with distributed medium access control is the IEEE 802.11 standard “Wireless LAN and medium access control (MAC) and physical layer PHY) specification”, 1999. A network in accordance with IEEE 802.11, or another wireless communication network may provide for a distributed access control to use communication resources, wherein, if a communication device wants to transmit a chunk of information or data packet on a transmission path covering a plurality of nodes of the network, it first contends for access. Generally, this contention is made at each of the participating nodes.
However, if further data packets are to be transmitted via the transmission path, the access procedure is performed by each of the participating nodes for each data packet of a data packet flow, i.e., performed separately for each data packet, even if the data packets belong to the same data flow. This introduces a large overhead, as the transmission of each single packet is negotiated.
Moreover, individual transmission of each packet may very well lead to different transmission paths for the individual packets, which in turn may lead to different transmission delays for the packet and sequential packets of one data stream may be received in reversed order. This causes problems in delay sensitive applications such as voice or real time transmission, resulting in reduced end-user perceived quality.